Posted
by
Unknown Lamer
on Wednesday June 27, 2012 @08:31AM
from the suddenly-babylon-five dept.

An anonymous reader writes with an update on DARPA's plans to rebuild satellites in orbit. "A year old DARPA program which aims to recycle satellites in orbit has started its next phase by looking for a guinea pig defunct satellite to use for evaluating the technology required. The program involves a Dr Frankensat 'complete with mechanical arms and other "unique tools"' and blank "satlets" to build upon.' Need parts! Kill the little one!"
If we're ever going to build space craft and other things in orbit, this seems like a great first step.

Then again, this project sounds like the scenes in all those hollywood movies where they throw a crapload of junk on a table and say, "We need to build a working relay station from only these parts!" Except in this case, it's using robots... in space!

Anyone got McGuyver's phone number? I'm sure he can get the robot to do *something* with the duct tape and swizzle stick.

Anyone got McGuyver's phone number? I'm sure he can get the robot to do *something* with the duct tape and swizzle stick.

Hmmm, duct tape.
Note to self: Pitch reality TV show to A&E hosted by Richard Dean Anderson and Steve Smith. Contestants must solve high-tech problems using only the household items that they are given. The items always include duct tape and empty beer cans.

Note to self: Pitch reality TV show to A&E hosted by Richard Dean Anderson and Steve Smith. Contestants must solve high-tech problems using only the household items that they are given. The items always include duct tape and empty beer cans.

Companies have been working on computer-driven cars for as long as I can remember. I can remember experiments on this similar to what Google is doing now even back in the 70's and 80's. Hell, they were talking about the idea even back before DARPA existed (anyone ever seen those old "What life will be like the future" shorts from the 50's?). They even made a TV show [wikipedia.org] about it.

Yeah, which is why I said "boost" not "they invented it". They made a lot of people aware of it through their high profile challenges and have dumped a lot of money into making it a reality. The prize money freed up a lot of university funding and the Stanford team in particular benefited. Your Knight Rider argument is so silly as to not being worth rebutting.

Products do not appear magically on the shelves at stores. Scientific advances do not immediately turn into things you can buy. They have to go through a research and design phase, which is what DARPA promotes. There's an engineering and application phase that follows, which DARPA isn't generally involved in. After that, there's marketing and commercialization, which is completely out of the realm of DARPA.

In the case of self-driving cars, you probably won't be able to buy one for personal use on the highway for a long, long time. In the shorter term, you may be able to ride in an automated taxi at a resort. You might see automated trucks that follow a human-driven truck on the interstate. You might see cars that can park themselves. It'll likely be a long time before you can buy a personal automated car for use on the public streets.

Self driving vehicles is probably a bad example. The tech is actually there - it's the infrastructure that's a bitch. Of course, that happens to be true for lots of tech things. Widespread adoption of a particular technology depends on much more than available hardware and software. The wetware has to be interested and available. Costs are a factor. Luck, the economy and perhaps moon phases as well.

But not to worry. The first widespread use of autonomous vehicles will likely be IED sweepers / screeni

If it works, great. If it doesn't, one collision can set us back *decades* in terms of the Kessler effect (i.e. space junk that makes it harder to launch/maintain orbit without more collisions).

If one collision is anywhere near likely to trigger the Kessler effect, wouldn't it have most likely happened by now?

After all, several nations have blown up satellites in orbit. That is far more likely to have caused the Kessler effect than a collision between two satellites resulting in an unknown, uncontrolled orbit. We already have satellites up there that are uncontrolled.

The obvious, incremental technology would be to build satellites so that they could be refueled on orbit

Launching craft into orbit costs a lot more than maintaining it in orbit or building new more advanced satellite. Your satellite refueling is ecofriendly, but burning old sats in atmosphere is more cost effective solution.

Isn't this the same agency that funded the corpse-eating robot? It all makes sense now. It will kill and eat astronauts and cosmonauts for power. Then it will make copies of itself from various satellites. Finally, it's clone army will come to Earth and devour us all.

It's ridiculous is what it is. Tons of fuel and energy to course correct in 3D and do computer calculations without a fixed anchor point. Gravity is excellent for making sure things hold together the way you want; weightlessness is excellent for making things move in a slow, controlled manner. Too bad weight and mass are two different things.

We can't absolute match speeds, stuff drifts and pushing against something causes lots of shifting with nothing to reset the momentum. Leveraging against gravity is

It probably won't waste that much more fuel to get from LEO to the moon, the one place with any significant gravity consistently nearest the Earth. But the equation changes greatly when you have to land stuff then hurl it back into space (the reason perhaps why the Russians are bold enough to offer cow jumps over the moon but not visits to the Apollo landing site). A cost-effective moon-based manufacturing requires the development of a mining

It's generally a stupid idea but there's a lot of stuff in similar orbits (eg. geostationary orbit over the US) that could mean doing it more than once with sane amounts of fuel. Of course getting to the far side of even the same orbit (eg. over Indonesia) is going to cost.

I just hope this doesn't turn into a long and pointless tranfer orbit thread populated with people that don't understand that ellipses exist (and that changing to a different location in the same orbit doesn't come for free) like the la

It refers to an extremely painfull earlier thread on this topic which consisted of trying to explain moving between orbits (and to different angles in the same orbit) to people that refused to consider anything other than circles so would not believe what you've written above:(You've put it well, and you've got a point that changing phase isn't all that expensive given enough time in comparison to station keeping costs.

You pretty much get to keep the perhaps decades obsolete electronics and the chassis, and those don't weigh much. So if you have to launch 80% of the mass of a new satellite to get a remanufactured old satellite, you're better off launching 100% of the mass for a completely new satellite that was integrated and checked out on the ground.

You can also imagine the agony if after rebuilding a week later the 25 year old battery charger fried wasting all the work.

There's a reason why old cars are scrapped instead of merely replacing the rusty chassis, worn engine, worn transmission, worn tires, worn suspension, rusted dinged body panels, worn carpet, ancient/obsolete cassette player radio... If the only thing you're keeping is the comfy drivers seat, just remove it and place it in a new car, if you must, because it makes no financial sense to replace "everything else" on the old car.

That's a conspicuous consumption situation. "Hey girls, look at me, I've got the pull to drive a fully restored 54 stude" or whatever. There's probably some political statement about driving cars made by the great satan to the north rather than just importing eurasian cars.

We could do that with frankensats. Hey we don't have a heavy lifter anymore and have to go begging to the euros and russkies but F you guys we'll spend ten times as much just to prove we don't need you. Or hey you foreigners, you suck

Are you kidding??? Do you have any idea how abjectly destitute the average Cuban is, thanks to Castro? They may have great health care and education, but that's about it. I talk to Cubans regularly via amateur radio, and I'm constantly amazed at how well they manage to keep their radios going with nothing more than spit and bailing wire.

The only reason they drive 50's vintage cars is because that's all that were on the island at the time of Castro's takeover - no one can afford a new car, even if they were allowed to import one!

From wikipedia [wikipedia.org]:"Typical wages range from factory worker's 400 non-convertible Cuban pesos a month to doctor's 700. That is around 17-30 U.S. dollars a month.""After Cuba lost subsidies in 1991, malnutrition resulted in an outbreak of diseases and general hunger.""Pensions are among the smallest in the Western hemisphere at $9.50. In 2009, Raul Castro increased minimum pensions by 2 dollars, which he said was to recompense for those who have "dedicated a great part of their lives to working... and who remain firm in defense of socialism"."

Do you have any idea how abjectly destitute the average Cuban is, thanks to Castro?

And definitely not to do with the US-led economic embargo, right?

Sarcasm aside, seriously- it's the embargo. Whether you're pro-Castro or pro-USA, everyone admits it's the embargo that's done the economic harm. The Cubans admit it because it's evidence that their problems are not of their own making, and the Americans admit it because it justifies their action (economic harm is exactly what the embargo was designed to do).

There's a reason they went further down the pan after the collapse of the Soviet Union

I think you're missing that the embargo is pretty much a US only thing and only the elite can afford the car and the gasoline... the average cuban dude doesn't have a personal american made car from 1950.

The Russians had decades to flood the island with their cars, eighty zillion european and asian countries have normal relations with Cuba.

I stick by my argument, they are just showing off by driving old cars. Plus or minus some confiscatory tax avoidance (like maybe a 100% sales tax, or a 50% annual prop t

Under current law, they [Cuban citizens] can only freely buy and sell cars that were on the road in Cuba before Fidel Castro's 1959 Revolution. Russian Ladas and modern Peugeots and Kias now outnumber the 1950s classics, but, for the most part, they are owned by the state and cannot be sold on the free market.

Most people can't do their own work. Therefore cars reach a point where repairs cost more than the car is worth. If they could, then scrapping it makes far less financial sense than refurbishing the worn parts.

Building reliable satellites is a long and expensive process, even in the best of situations here on earth. Re purposing an already built and flying one in space is surely going to be even worse, producing really expensive and unreliable satellites in the process.

This is like trying to do an overhaul of a fighter jet avionics while the thing is in flight. Yea, you could possibly do it, but why would you want too try?

Now if they want to start designing into satellites a way to make re-provisioning of satel

In flight? No, it's more like repairing a ship while at sea (because the satellite doesn't have to maneuver itself while it is being repaired). Ships are repaired at sea on a fairly regular basis, at least enough for them to limp back to port. If there were no ports available, it wouldn't be that much of a stretch to fully repair and resupply them with floating drydocks. It would help if there were humans there, of course.

In flight? No, it's more like repairing a ship while at sea (because the satellite doesn't have to maneuver itself while it is being repaired). Ships are repaired at sea on a fairly regular basis, at least enough for them to limp back to port. If there were no ports available, it wouldn't be that much of a stretch to fully repair and resupply them with floating drydocks. It would help if there were humans there, of course.

So all this just begs the question, what kind of efficiency are they expecting to gain? Are we trying to lower launch costs by not having to lift heavy components into space? Well launching the equivalent of a dry dock is *not* going to be cheap.

I'm sure that this has NOTHING to do with the X37, and any conceivable plan to disable/grab/dissect/plunder Chinese/Russian satellites in orbit.

No, no, we're going to send a multimillion-dollar mission aloft to repair and enable broken space junk that even if restored to functional within a year or three is grossly outdated by new advances in hardware.

Sounds plausible, actually. It's a handy repair tool, plus it can open up the enemy spy and communications sats and jack in directly to get at precious unencrypted data. Spy on the spies, intercept communications, maybe even discover their keys.

small "microsats" with a single use booster. Release one that attaches to the target and then fires it's booster to deorbit the target. IF you used a solid fuel rocket you could make it very small and highly effective.

Freshly printed money? What are you, some kind of stone age, vacuum tube, hippie Mennonite or something? Some clerk at the central bank simply enters a number on a computer screen, and the funds are in your account as soon as they click OK. Paper money... Phhhft!

... Seattle's recycling program, were going to have to separate the navigation, communications and orbiting thermonuclear weapons platforms. And we will have to remove and fold the solar panels. Then we'll have to have them in the correctly marked bin, ready for pickup on Wednesdays.

Too much trouble. I'm just going to dump them on the nearest passing asteroid.

I have a strange idea. What if its not Frankenstein like but more "siamese twin" like?

So the batteries fail on this sat and the charger on another sat, duct tape them together, run an extension cord... Yes I realize its not always going to be simple and there are no world wide standards. But its interesting to think about "siamese twin" sat work instead of the provided assumption/example of Frankenstein work.

Imagine a comsat with nearly full positioning fuel tanks and good thrusters and dead traveling wave tubes in the transmitter section or the antenna failed on deployment or whatever, duct taped to a perfectly working comsat with nearly empty positioning tanks...You may not even have to do wiring, some weird scenarios might require nothing other than two arms and a roll of duct tape, or aerospace grade kapton tape or whatever they use. I imagine just mushing them together might have some interesting thermal issues, those could be worked around, probably.

To do ANYTHING yes you'd need a full orbiting machine shop, and a full SMD rework station, and probably a solar powered foundry to make castings. But as decades (centuries?) of high tech redneck engineering proves, you can none the less do a hell of a lot with just duct tape, jb weld, and bailing wire. You can imagine this looking all liquid metal terminator 3 or whatever, but I'm thinking its gonna look a lot more "hold my beer and watch this"

I would mod you up if I had any mod points. This is exactly what I had envisioned as well. Other than the potential of more debris from space junk if a crash occurs, what would prevent this from happening?

You can't just duct tape and weld parts together to make a functioning satellite. Whenever a satellite (or spacecraft for that matter) is designed, it's one person's job to track the weight, inertia tensor, and location of every part which goes into the satellite. Yes, even the duct tape. The reason is that the overall inertia tensor of the satellite (a 3x3 matrix) has to be symmetric and oriented properly to be able to control the satellite when spinning or rotating it. If it's not, its angular momentu

What we need is a kind of "space truck" that can take astronauts up into space, let them live and work for weeks at a time while working on these satellites, and possibly bring them back from orbit. It would be great if this "space truck" was reusable as well. The added advantage is the government isn't beholden to foreign or private entities when we need to conduct repair or salvage operations in space.

This is essentially a satellite grabber. It can "dock" with a satellite, attach things to it (presumably drill holes in it, too) and make the satellite do things - either things it used to be able to do, or things you'd like it to be able to do.

One thing that would be nice to do would be to deorbit large, useless satellites that are occupying prime orbital slots. Or to add controlled destruction to satellites that failed and are out of control (though I'd be surprised if this thing could stop a tumbling sa

Other posters have already observed some of the obvious flaws in this scheme.

Satellites fail, for the most part, when their rechargeable batteries quit and/or their consumable manoeuvring fuel runs out. These are among the heavier components aboard many satellites, so our hypothetical 'repair and resupply' launch is already going to be costly and heavy before you add all that unique and highly flexible hypothetical manipulator hardware. From any sort of rational economic standpoint, if you're going to launch a heavy, expensive satellite, you might as well launch a replacement (with all-new hardware, up-to-date electronics, incorporating the lessons learned from the previous iteration, etc.) instead of trying to fix or cannibalize the dodgy one in orbit.

Trying to service multiple satellites with one launch of our Swiss-Army-knife repair droid gets even worse, because manoeuvring between orbits tends to be very costly in terms of fuel (prohibitively so if a significant change in inclination is contemplated) and therefore weight.

And how user-serviceable are most satellites? Anything that's already in space now (or that is likely to be launched in the next decade) hasn't been designed to be repaired, modified, or scavenged after launch. Are we really solving the 'space junk' problem if our repair droid is inadvertently leaving behind a cloud of dropped screws and broken hardware? One satellite is easy to track and avoid. A haze of screws and plastic chips is not--and will still put a hole right through the ISS.

The folks at DARPA are sometimes crazy, but they're not usually idiots. Presumably they've been able to come up with the same objections as Slashdotters, and they probably realized them faster than we did. So what's really going on?

1) A stripped-down version of this tool could be used to attach de-orbiting or manoeuvring thrusters to disabled satellites that happened to be occupying (or threatening) particularly high-value orbital real estate. The ISS has to be periodically repositioned to avoid the occasional bit of space junk. Further up, there's a limited amount of space in geostationary orbit, and a malfunctioning satellite could be trouble as either a source of physical or radio clutter. If the program fails to produce its rather pie-in-the-sky 'dream' goal, it could still develop this useful sideline.

2) The military would love to have the capability to selectively damage, disable, and/or capture 'enemy' space hardware. This program would complete nearly all the steps required to develop such a capability, but under the shiny, happy patina of putative civilian applications.

1) A stripped-down version of this tool could be used to attach de-orbiting or manoeuvring thrusters to disabled satellites that happened to be occupying (or threatening) particularly high-value orbital real estate. The ISS has to be periodically repositioned to avoid the occasional bit of space junk. Further up, there's a limited amount of space in geostationary orbit, and a malfunctioning satellite could be trouble as either a source of physical or radio clutter. If the program fails to produce its rather pie-in-the-sky 'dream' goal, it could still develop this useful sideline.

I think this is the real reason, at least in the beginning. Prime orbital slots are getting scare and you can't make new ones. Getting RID of the junk by deorbiting the stuff makes sense, is technologically feasible and doesn't require the tool waving and silly economics of bringing duct tape to low earth orbit.

Of course, EVENTUALLY you need to learn how to fix things in orbit. The ISS and the Shuttle / Hubble repair missions have shown that we can do baby steps but we need to develop capabilities far in

I thought the line was "Need parts! Kill the fat one." not kill the little one.

If they can reuse parts from older satellites or reuse the old satellites that would be a good thing. They may be able to get rid of some of the bigger "space junk" that is up there. I am not sure if anything can be done with the paint chips and other smaller parts zipping around up there. Making a space dragger like the fishing boat dragger would also "catch" useful satellites.

If you send up a launch vehicle, and have it latch onto an existing orbiter, cant you use something to push the old satellite towards Earth. And push yourself into a higher orbit? It seems like it might be more efficient than hurling matter out of booster engines. You could use electromagnetic force.Can you use pre-existing orbiters as "stepping stones"?

The electronics have a limited lifetime, the satellites probably have no maneuvering fuel, and aren't designed to be taken apart or refueled.

Use an ion-drive, solar powered 'tug' that goes from LEO to Geo-stationary orbit. Take a new satellite up, drop it off, find the nearest dead satellite, and use the tug to de-orbit the satellite as it returns to LEO. Using an ion-drive vehicle keeps refueling costs for multiple missions low.